Indigo Airlines — they did not allow me to board the flight

Dear authority on 12th june 2015, i was supposed to board flight from Dubai to Mumbai which was scheduled at 11.25 am. I reached airport around 10.30 am, when i reached check-in counter one of your staff member was closing off. I requested her to check in but she refused saying that you are 5 minutes late. I apologised on being late then to also she just walked off. Then i roamed everywhere in Dubai airport if somebody can help me out to board the plane but nothing worked out. Eventually i wasn't able to board my flight. At last i called the customer and asked for my refund as its a refundable ticket But still nothing has been sorted out. Mohammed Hussain Ticket no. DEH83R